iOS键盘高度的获取

代码如下：

- (void)viewDidLoad
{
    [super viewDidLoad];

    //增加监听，当键盘出现或改变时收出消息
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    //增加监听，当键退出时收出消息
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];    
}

 //当键盘出现或改变时调用
- (void)keyboardWillShow:(NSNotification *)aNotification
{
    //获取键盘的高度
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
   int height = keyboardRect.size.height;
}

//当键退出时调用
- (void)keyboardWillHide:(NSNotification *)aNotification
{

}

高度值其实就只有两种类型，一个是Default一个是Number

①以下几种键盘类型几乎一样，键盘高度也是一样的

UIKeyboardTypeAlphabet
UIKeyboardTypeASCIICapable
UIKeyboardTypeDefault
UIKeyboardTypeEmailAddress
UIKeyboardTypeNamePhonePad
UIKeyboardTypeNumbersAndPunctuation（数字和标点符号）
UIKeyboardTypeTwitter
UIKeyboardTypeURL
UIKeyboardTypeWebSearch

5.5吋271

4.7吋258

4.0吋253

②以下几种键盘为数字类型的键盘，键盘高度也是一样的

UIKeyboardTypeDecimalPad（带小数点的数字键盘）
UIKeyboardTypeNumberPad（纯数字键盘）
UIKeyboardTypePhonePad（带*+#,;的数字键盘）

5.5吋226

4.7吋216

4.0吋216